Averhoff Reservoir - 2008 Survey Report

Prepared by Randy Myers and John Dennis
Inland Fisheries Division
District 1-D, San Antonio, Texas

This is the authors' summary from a 16-page report. For a copy of the complete report, use the download link in the sidebar.

Fish Populations in Averhoff Reservoir were surveyed in 2008 using electrofishing and in 2009 using gill nets. This report summarizes the results of the surveys and contains a management plan for the reservoir based on those findings.

Reservoir Description

Averhoff is a 174 acre narrow, riverine-type reservoir located on the Nueces River, near Crystal City, TX, in Zavala County. It was constructed by the Zavala-Dimmit Water Improvement District Number 1 in 1948 to provide water for agriculture, recreation, and flood control. Water level is not recorded for this reservoir. Access was fair with only one public ramp, and there were no handicap specific facilities. The primary shoreline habitat was overhanging brush, and native-submersed vegetation occupied 36 acres (20.7%).

Management History

Important sport fish included largemouth bass and channel catfish. Harvest of both species was managed according to standard state-wide regulations.

Fish Community

• Prey species: Bluegill and gizzard shad abundance was greater in 2008 compared to previous years. Populations of these species were composed of a sufficient number of small individuals suitable as prey for predators.
• Catfishes: Channel catfish abundance was greater in 2009 than in previous years. The population remained mostly comprised of fish >16 inches.
• Largemouth bass: Largemouth bass abundance was greater in 2008 than in previous years. Although population size structure was improved in 2008, few fish >14 inches were present in the population.

Management Strategies

• Based on survey results all species should continue to be managed under current harvest regulations.
• Monitor fish populations with standard sampling conducted every fourth year (2012-2013) and conduct additional electrofishing in fall 2010 for the purpose of providing a more in-depth assessment of the forage base, primarily shad populations.

Performance Report as required by Federal Aid in Sport Fish Restoration Act Texas Federal Aid Project F-30-R-34 Statewide Freshwater Fisheries Monitoring and Management Program